The present invention relates to a rotary and/or slide valve for controlling the discharge of molten metal from a metallurgical vessel, the valve including a fixed refractory outer valve part and a rotary and/or slidable refractory inner valve part disposed within the outer valve part and establishing a seal therewith, wherein the outer valve part defines an inlet of the valve and an outlet of the valve spaced from the inlet, and the inner valve part has a connecting channel and is movable to an open position of the valve at which the connecting channel is open to the inlet and outlet of the valve. The present invention also relates to a refractory outer valve part and to a refractory inner valve part employable in such a valve, and to an assembly in which such a valve is embedded in a portion of the refractory lining of a metallurgical vessel.
One type of such a valve is disclosed in German application P 38 05 071.4. In this valve, the connecting channel of the inner valve part extends radially therethrough. Thus, the connecting channel significantly contributes to a lack of strength of the inner valve part.
Furthermore, it is relatively time-consuming to perform maintenance on the inner valve part such as widening the connecting channel when such becomes clogged or reconstructing the inner valve part by reducing the width of the connecting channel when the same has become widened by the deterioration of the portion of the inner valve part surrounding the connecting channel.
Finally, when the inner valve part is rotated to place the valve in the closed position, both the inlet and the outlet of the valve are closed by the inner valve part. Accordingly, when in such a position, a portion of the molten metal is enclosed in the connecting channel and can harden there causing obvious problems including those requiring the maintenance described above.
Another valve of the aforementioned type is disclosed in DE-PS 35 40 202. This valve is unsuitable for use with an elongated nozzle in a metallurgical vessel. In this valve, a tubular inner valve part extends partially within an outer tubular valve part, and the inlet and outlet of the valve extend radially through the outer valve part while the connecting channel of the inner valve part is defined by a pair of openings extending radially through the inner valve part. A substantially similar type of valve is disclosed in U.S. Pat. No. 3,651,998. As mentioned above, the radial openings contribute to a lack of strength in the respective valve parts.
European Patent Publication No. 0 078 760 discloses a roller-type rotary valve. This valve can only be mounted to the exterior of a metallurgical vessel. This valve also presents a disadvantage in that a significantly large force is required to maintain the two rollers constituting the valve against one another. Furthermore, only a line of contact between the rollers establishes a seal of the valve and, therefore, sealing is suspect in such a valve.